Process for the recovery of metal oxids and hydroxids.



- ids, of which the following is a specification.

ARNOLD or'ro BLIGKLE, or FRANKFORT-ON-THE-MAIN, GERMANY, AssIeNoR' TOTHE CORPORATION or METALLBANK UND METALLURGISCHE GESELLSCHAFT A. G., 0F

FRANKFORT-ON-THE-MAIN, GERMANY.

PROCESS FOR THE RECOVERY OF METAL OXIDS' AND HYDROXIDS.

No Drawing.

To all whom it may concern:

Be it known that I, ARNoLoO'rro BLICKLE, diplomad engineer, a citizen ofGermany, residing at Frankfort-on-the-Main, in the German Empire, haveinvented certain new and useful Improvements in Processes for theRecovery of Metal Oxids and Hydrox- The present invention .relates tothe recovery of metal oxide andhydroxids and in particular 'toa processfor transforming basic precipitates of salts obtained by precipitationof metal salt solutions with basic substances into practically pureoxide or hydroxids, which process also permits of a separation ofseveral metals. For this purpose according to the present inventionbasic salt precipitates obtained by precipitating metal salt solutionswith basic substances in quantities substantially equivalent to themetal content of'the solution are heated to a moderate temperature, thatis to say, to a temperaturebelow the boiling point of the salts and theresidue is then lixiviated. The heating may also be carried out in anautoclave in the presence of water, in which case p of course the saltsformed are dissolved;

As an example it has been shown that the recovery of oxids or hydroxidsof copper and zinc which are practically free from .chlorin, can becarried out in the following manner: To a solution of copper and zincchlorid there is added aquantity of burnt lime which is substantiallyequivalent to its content in metal, whereby the copper and zinc areprecipitated in the form of the free oxids or.-hydroxids and freechlorids well-known green precipitate containing a good amount ofchlorids and of-course also containing unused lime. The filteredprecipitate is now dried and heated to a moderate temperature, below theboiling point of the chlorids, for instance at 500 centigra'de. Thisheating can be carried out in the open or in closed vessels;iand theheating means may consist of hot gases" or superheatel' .ste'am. It willbe seen that first water is,

givenl'oif and that afterward the color of the precipitate changesfromgreen to gray. A splitting up of the oxy-chlorids takes place,."that to say, water is separated and are formed. 'FThe product thusobtained is now lixiviated with water. when the chloride,

Specification of Letters Patent. Patented lw 14 1916 Application filedSeptember 24, 1913. Serial No. 791,563. 7

and principally calcium chlorid, go intosolution. The residue isvpractically free from chlorin.

In using the same principle of the process it is also possible to attaina practically complete separation of copper from zinc from theirsolution. For this purpose to the copper-zinc solution a quantityequivalent only to its content in copper of for example be present toform copper oxid, zinc chlorid,

and calcium chlorid. By treatment with water the chlorid may belixiviated out from the products and practically pure copper oxidremains. The dissolved zinc. is then obtained practically free fromchlorin by precipitation with lime and treatment as above described.

It will be obvious that in place of lime other basicsubstances can beemployed for the precipitation of the metals; for instance, copper maybe precipitated with zinc oxid. Likewise, it is not necessary to startwith a chlorid solution, other salt solutions, such for instance as"'-solutions of sulfates being capable of beingtreated .in the same manner.

.As stated above, to a solution of metal salts is added a quantity ofbasic substances which is substantially equivalent to its metal content.Such determined uantity of basic substances is required for t econversion of the basic salts into'oxids which is done after Iprecipitation. For the precipitation itself a rated, to a moderatetemperature, below the boiling point of the ing the residues.

2. The process of effecting a selective recovcry of metal oxids andhydroxide from metal salts, and then lixiviatsalt solutions whichcomprises treating such 'thereby effecting the COIIVBISiOIl'Of such"solutions with basic substances in amount not exceeding the equivalentof'the metal to be separated and thereby forming a basic saltprecipitate, heating the precipitate with an amount of basic substancessubstantially equivalent to the particular metal or metals -to beseparated, to a moderate temperature,

below the boiling point of the salt, and

metal or metals into oXids and hydroxids,

i and lixiviating the residues for the recovery of the desired metalcompounds in a substantially pure state;

v 3. The process of recovering metal Oxide and hydroxids from metal saltsolutions,

" which comprises treating such solutions with small amounts of basicsubstances just sulficient for precipitating the'metalcontent to beseparated and thereby forming a basic salt precipitate, heating thebasic precipi- "t-ate with further amounts of basic substancessuificient to form, with the basic substances previously added, theequivalent of the metal to be separated, to a moderate temperature,below the boiling point of the salts, and then lixiviating the residues.

4. The method of efiecting a selective recovery of metal oxidsandhydroxids from metal salt solutions, which comprises treating suchsolutions with a small amount of basic substances just sufficient toprecipitate one or more of the metals of the solution and therebyforming basic salt precipitates of such metal or metals, heating thebasic precipitates with further amounts of basic substances suflicientto form, with the basic substances previously added, the substantial 1equivalent of the metal or metals tobe sepa-' rated, to a moderatetemperature, below the boiling'point of the salts, and thereby efl'ecting substantially complete conversion of said metal or metals intotheir oXids and hydroxids, and then lixiviating'the residues for therecovery of the desired metal com-,

pounds in a substantially pure state.

5; The process of recovering metal oxids and hydroxids from metalchlorid solutions,

which comprises treating such solutions with basic substances in amountsufficient to form basic chlorid'precipitates, heating the basicprecipitates with basic substances substantially equivalent to theamount of metal to be separated, to a moderate, temperature, below theboilingpoint of the salts, and then lixiviating the residues. I

In testimony whereof, afiiX my signa ture in the presence of twosubscribing Witn'esses, I

ARNOLD O T'IO BLIoKLE.

Witnesses:

ROBERT ENGLER, v JEAN GRUND.

